The Rubber Band — Rex Stout

THE PLEDGE OF THE RUBBER BAND
... began in Silver City, Nevada, at the turn of the century. When the whole mess fell into Nerds lap, the sedentary detective and Archie Goodwin had to crack a mystery that stretched across four decades and five thousand miles--a mystery involving a noble English family, an escapee from a lynch mob, multiple murder, blackmail and a lovely, lethal client!